System and method for providing improved trench isolation of semiconductor devices

A semiconductor structure, comprising:

• a silicon dioxide liner comprising a first portion in a trench of a substrate and a second portion over one or more horizontal portions of the substrate that are adjacent to the trench, wherein the second portion of the silicon dioxide liner comprises a first top and a first side, the first side extending from the first top to the substrate;
• polysilicon material deposited in the trench and over the trench, wherein at least one portion of the deposited polysilicon material extends laterally over at least one edge of the trench, wherein the at least one portion of the deposited polysilicon material comprises a second top and a second side, the second top comprising a notch, the second side extending from the second top to one of:
• the silicon dioxide liner and the substrate, wherein the at least one portion of the polysilicon material completely covers the first top of the second portion of the silicon dioxide layer;
• and
• a layer of oxidation material over the at least one portion of the deposited polysilicon material, wherein the layer of oxidation material contacts the second top and the second side of the at least one portion of the deposited polysilicon material and fills the notch in the second top of the at least one portion of the deposited polysilicon material.

A semiconductor device, comprising:

• a substrate;
• a trench in said substrate;
• a silicon dioxide liner, comprising a first portion in said trench and a second portion over one or more horizontal portions of said substrate that are adjacent to said trench, wherein the second portion of the silicon dioxide liner comprises a first top and a first side, the first side extending from the first top to the substrate;
• polysilicon material comprising a first portion filling the trench and a second portion over said filled trench to protect said silicon dioxide liner, the second portion of the polysilicon material extending laterally over at least one edge of the trench, wherein the second portion of the polysilicon material comprises a second top and a second side, the second top comprising a notch, the second side extending from the second top of the second portion of the polysilicon material to one of:
• the silicon dioxide liner and the substrate, where the second portion of the polysilicon material completely covers the first top of the second portion of the silicon dioxide layer;
• and
• a layer of oxidation material over the second polysilicon material, the layer of oxidation material contacting the second top and the second side of the second portion of the polysilicon material and filling the notch in the second top of the second polysilicon material.